[release/10.0] Improve Blazor reconnection experience after the server is restarted

[oroztocil]

Backport of #64732 to release/10.0
Fixes #64228

Description

In .NET 10, resuming a Blazor circuit fails when the server has been restarted (and an out-of-process persistent storage is not used). Currently, this is handled on the client side by displaying a "reconnection failed" UI which requires the user to manually reload the page and can show confusing messages to the user. Previously, in .NET 9 the page would reload automatically once the server has restarted.

This PR re-adds the default reloading behavior and fixes other UX issues with the reconnection worklow.

Customer Impact

The issue makes the reconnection UX worse for any Blazor Server app updated or created with .NET 10. It also impairs the developer experience as developers often rebuild and restart the server application.

Regression?

• Yes
• No

The observable behavior regressed from .NET 9.

Risk

• High
• Medium
• Low

Fix mostly restores behavior to previous state.
Apart from removing one error message sent by the server, all changes are in the client-side JS code that can be overridden by the users if necessary.

Verification

• Manual (required)
• Automated

Packaging changes reviewed?

• Yes
• No
• N/A

[Copilot]

Pull request overview

This PR improves the Blazor Server reconnection experience after a server restart in .NET 10 by restoring the automatic page reload behavior from .NET 9. When circuit persistence is not available, the client now automatically reloads the page instead of displaying a confusing "reconnection failed" UI that requires manual intervention.

Key Changes:

• Modified client-side reconnection logic to automatically reload the page when the server rejects both reconnection and resume attempts
• Updated error messages to be more user-friendly by offering retry options before requiring a page reload
• Removed server-side error message that was sent when circuit state couldn't be retrieved, allowing the client reconnection logic to handle the scenario gracefully

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/Components/Web.JS/src/Platform/Circuits/DefaultReconnectDisplay.ts	Updated button visibility logic and error messages during reconnection/resume failures to show retry option
src/Components/Web.JS/src/Platform/Circuits/DefaultReconnectionHandler.ts	Removed unnecessary pause UI display before resume attempt, streamlined to call rejected() directly on failure
src/Components/Web.JS/src/Platform/Circuits/UserSpecifiedDisplay.ts	Made reconnect/remote fields public and added remote parameter to resume-failed event for consistency
src/Components/Server/src/ComponentHub.cs	Removed error notification to client when circuit state unavailable, allowing client to handle gracefully
src/Components/Server/test/Circuits/ComponentHubTest.cs	Removed test assertion for error message that is no longer sent
src/ProjectTemplates/Web.ProjectTemplates/content/BlazorWeb-CSharp/BlazorWebCSharp.1/Components/Layout/ReconnectModal.razor	Improved error message and moved Resume button to be visible in both paused and resume-failed states
src/ProjectTemplates/Web.ProjectTemplates/content/BlazorWeb-CSharp/BlazorWebCSharp.1/Components/Layout/ReconnectModal.razor.js	Changed catch handler to show resume-failed UI instead of immediately reloading
src/Components/test/testassets/Components.TestServer/RazorComponentEndpointsStartup.cs	Added configuration option to disable circuit persistence for testing reconnection without server state
src/Components/test/E2ETest/ServerExecutionTests/ServerReconnectionWithoutStateTest.cs	Added comprehensive E2E tests for reconnection scenarios with both default and custom UI